The Incidence of Radiographic Markers of Idiopathic Intracranial Hypertension in Those With Spontaneous Cerebrospinal Fluid Leak.

BACKGROUND AND OBJECTIVES: Increased intracranial pressure as seen in idiopathic intracranial hypertension (IIH) can lead to spontaneous cerebrospinal fluid (CSF) leaks. However, CSF leak may relieve classic signs of increased intracranial pressure, leading to a missed diagnosis of IIH. The presence of radiographic markers of IIH may be one method to predict the diagnosis without high lumbar puncture pressures. We evaluate the incidence of radiographic markers classically associated with IIH in those with spontaneous CSF leaks. METHODS: A review of the electronic medical record was conducted for patients admitted for spontaneous CSF leak between January 2012 and December 2022. Demographic, radiological (optic nerve sheath diameter, presence and degree of empty sella turcica, Meckel cave size and volume), and clinical (ophthalmic examination findings, presenting symptoms, IIH diagnostic status) data were collected. RESULTS: Thirty patients (mean age: 51.7 years) were included in the analysis. Of 14 patients with recorded preoperative or intraoperative LP pressures, 5 met the criteria for diagnosis of IIH based on elevated lumbar puncture pressure (>25 cm H2O). One of 30 patients presented with papilledema. In total, 22/24 (91.7%) patients with Meckel cave measurement had dilated volume (>540 mm3), 18/25 (72.0%) patients had dilated optic nerve sheath (>5.17 mm), and 15/26 (57.6%) patients had an empty or partially empty sella on MRI. CONCLUSION: This study provides us an incidence of IIH associated radiographic markers in the CSF leak population. Further study is needed to investigate if radiographic parameters in these patients may assist in diagnostic criteria of IIH given that papilledema and elevated lumbar pressures may not be present.